To get an intuitive feel for charged knots, let us begin with an example that appears in every undergraduate course on electricity and magnetism [1]}. Consider a perfectly circular and uniform loop of static charge. By symmetry, or by using Coulomb's law, one can prove there is an equilibrium point at the center of the circle. Moreover, the symmetry of the situation suggests that the equipotential surfaces enclosing the circle are nested tori, at least sufficiently close to the circle. Far from the circle, they must approach spheres, because a circular loop of charge looks like a point source in the far-field.
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